let input = `15 _
I love GPLT`
let input_arr = input.split('\n')



let arr = input_arr[0].split(' ')
let word_length = parseInt(arr[0])
let pad_char = arr[1]


let msg = input_arr[1]

if(word_length <= msg.length){
let submsg = msg.substring(msg.length - word_length, msg.length)
    console.log(submsg);
}
else{
    let padstr = pad_char.repeat(word_length - msg.length)
    console.log(padstr+msg);
}